Gamma delta T‐cells regulate myeloid cell activity after injury

Abstract

Gamma delta (γδ) T‐cells have been shown to be important in post‐burn inflammation and wound healing, but their role in the regulation of myeloid cells is unknown. To study this wild‐type (WT) and γδ T‐cell deficient (δTCR−/−) mice were subjected to a major burn or sham treatment. Three days later skin was collected and subjected to dispase/trypsin digestion or frozen. The number of CD11b+ myeloid cells increased by ~70% in the wound skin of WT mice. This was due to increased numbers of myeloid‐derived suppressor cells (MDSC; CD11b+ GR1+), as macrophage (Mϕ; CD11b+ F4/80+) numbers decreased by ~80% after burn. In δTCR−/− mice, burn increased myeloid cell numbers 7‐fold due to both a MDSC (20‐fold) and a Mϕ (3‐fold) influx. Burn also increased skin cytokine levels for IL‐1β, IL‐6, TNF‐α and MIP‐1β. TNF‐α, MIP‐1β levels were further elevated in the injured skin of δTCR−/− mice. In conclusion these data show that γδ T‐cells regulate myeloid cell infiltration of the wound site and act to quell inflammation. NIH grant GM079122